Production of artificial materials



Patented June 16, 1936 4 i "QVUNYITED T PATENT/OFFICE],-

' v PnonUo'rIoN or ARTIFICIAL MATERIALS} Erich Kuehn, Mannheim, and Heinrich Hopfl', v 'Ludwigshafen-on-the-Rhine, Germany, assignors to I. G. Farbenindustrie Aktiengeselischaft, Frankfort-on the-Main, Germany No Drawing. Application April 17, 1933, Serial No. 666,544. lnGermany May 14, 1932 a clai s. (01. 260-2) The present invention relates to the produce in a substantially anhydruai. e. an anhydrous tion of artificial materials from polymerized vinyl I or practically anhydrous, medium, while removing alcohol and aldehydes. e the water formed during the reaction. It is known in the art that diflferent modifica- Aldehydes of any kind may be. employed for 5 tions of polymeric vinyl alcohol can be obtained the reaction, :lor example aliphatic aldehydes.

owing to the different methods of the production such as formaldehyde, acetaldehyde, propionof the polymeric alcohol which may be, prepared aldehyde, butyraldehyde, dodecyladlehyde, octofor example by a more or less strong-polymerizadeoyla de y eretonaldehyde, O y e y tion of vinyl acetate,'or of vinyl chloracetate and 2-ethylcapronic aldehyde, cyclic aldehydes, for e subsequent saponification oi the polymeric esters. x mp eyelealiphatic l ehy s. such as hex 10 The different modifications are generally equivahyd b nz d yd ati a d hy f u lent as regards their chemical properties but as benzaldehyde, chlorobenzaldehyde, cinnamic differ somewhat from each other in their physical a d hyd 0r lp t lap t d hy and I properties, such as solubility and viscosity of their he e oey aldehydes c s furo solutions. The said acid accelerators comprise substan- 15 It has already been proposed to prepare artitially anhydr u acids, hp ric, phos-. ficial materials by reacting the different modiphoric, 'chlorhydric, chioracetic, para-toluenefications of polymeric vinyl alcohol with aldehydes. sulphenie O methyl-t-suiphurie acids; these fields inthe presence of accelerators. Theinitial mate-- a nen-exidizing acids, in c t- 0 t rials may also be polymeric 'vinyl esters, the Permengenie ehlolie acids, 'Whieh cannot en saponification of the polymeric vinyl esters to emp y d f r th p p set nd d. Th sa form the corresponding polymeric vinylalcohols id a e at s r u l y p y in a being carried out simultaneously with the conamount between P thousand andvlo P densationof the latter with aldehydes; in this cent. preferably in an amount we 1 p condensation acetals are-probably formed. By thousand d 1 p cent by weight of t p 25 varying the amount of aldehyde employed, artivinyl alcohol. If the-said p lyv n l a c l h flcial materials having difierent properties may been Prepared y sellenifieetien f a P lyv n be prepared. Thus, for example, by employi ester by means of acid, itis not necessary to add A very small amounts of acetaldehyde,-products are, one of the said acid accelerators to the reaction obtained which are still soluble in waters By mix re beca se asufficient amount or acid is 30 employing larger amounts of aldehyde, the usually retained in the saponified polyvinyl solubility or capability of swelling in water of alcohol. If, however, the saponiflcation of the the product decreases until, when the ratio is 2 ester has been c d out y m s f alkali, mo ecular proportions of a polymeric vinyl alcohol the amount of acid accelerator must be suflicient $6 to 1 molecular proportion of acetaldehyde, the to-neutlalize any alkali Still Present and, morecapacity of the condensation product for swelling Over. to v a h ly acid reaction to the alcohol,

in water is usually practically removed; Genremoval of the Water m d m y e'rally'speakln it i necessaryjdemploy quaned by'absorbing the water during the reaction by tity or aldehyde in excess or that desired to take means of neutral substances av a st o 40 part in the reaction; the removal orremainders a -a s a t su as anhyd u 40 of aldehyde is, however, difllcult because, by um chloride, dehydrated sodium sulphate. n reason or its great reactivity, it gives rise to dreus c pper s p te, a hy ous sodiu acetate. resinification, the resulting 'r'esinl only being dehydrated magnesium or'calcuim sulphate and capable of separation with very great diflicult the like- It is especially advantageous, v r.

When employing aldehydes ,of high molecular to carry out the reaction in the. presence of an 45 weight, the removal of remai der o1 aldehyde inert diluent which is'insoluble in water, such as iromythereactio'n product is especially dlfllcult benzene, yl e chloride, m yl chloride. because these aldehydes are usually only volatile h m, carbon tetrachloride. ri hl r ylwith difficulty in steam and can frequently only ene, i h h benzine f i y h xbe incompletely removed by other methods. ane, mone l r n'zen 5o -"We.have'now found that very valuable artificial" benzene the like, the rm d ing (115- materials derived from the reaction. of the (111- tilled Ofi t e with the diluent during the Ierent modifications ofpolymeric vinyl alcohol action, If, h wever, the reaction is carried out and aldehydes, in the presence of acid ,acceler'ainthe presen e both of a diluent and of an inert tors. can be obtained by carrying out the reaction water-absorbing substance, the working tempera- 55 ture may be below the boiling point 01 the diluent .because in this case the water need not be removed by distillation. The diluent is usually employed in an amount equal to the weight of the reaction mixture up to 10 times said weight.-

As a result of the removal of the water formed during the condensation it is possible to bring the aldehyde employed quantitatively into reaction. The employment of anexcess of aldehyde and the consequent subsequent treatment of the reaction product for the removal of the unconverted aldehyde is therefore generally speaking dispensed with. By the said method it is also possible, inter alla, to prepare products in which only a part of the lrvdroxyl groups of the polymeric vinyl alcohol has entered into reaction with the aldehyde. While hitherto in order to obtain always uniform products. it has been absolutely necessary to adhere precisely and accurately to a specific method of working chosen (concentration, temperature and time) which has been calculated purely empirically, according to the present invention the amount of aldehyde entering into reaction may be most accurately controlled by determining the amount of water of reaction formed and it is possible thus to ascertain whether the ,desiredmroduct is already formed without the necessity for a careful maintenance of deflnite working conditions. Thus it is possible in 40 pure industrial mixtures containing aldehydes,

such as for example crude, commercial butyraldehyde or mixtures of aldehydes containing from 8 to 14, mainly 12 carbon atoms, such as may be obtained by the catalytic dehydration of mixtures of alcohols prepared by catalytic hydrogenation of fatty oils and fats, such as coconut oil, sperm oil, rape seed oil, cotton oil and the like.

The process of the \present invention allows inter alia of the production of new artificialmaterials. namely those from polyvinyl alcohol and those aliphatic aldehydes containing more than 4 carbon atoms in their molecule. w

When carrying out the reaction with polymeric vinyl carboxylates, such as polymeric vinyl acetate, formate or butyrate, the 'reaction is carried out in the presence of monohydric alcohols of low boiling point such as methanol, ethanol, propanol ,or butanol. A re-esteriflcation then first takes place as a result of which the esters of the added alcohols and the free polymeric vinyl alcohol .are formed, the latter then reacting with the aidehydeswith the splitting off of water. Also in this case the reaction is carried out, in accordance with the invention, in the presence of the said water-absorbing inert substances and/or of the aforesaid inert diluents.

The following examples will further illustrate the nature of this invention but the invention is not restricted tothese examples. The parts are by" weight.

Example 1 A mixture of v88 parts of polymeric vinyl alco- 1101, obtained by the saponification' of polymerized vinyl acetate dissolved in ethyl alcohol by means of sulphuric acid, 300 parts of methylene chloride and 44 parts of acetaldehyde'is gradually heated to boiling while stirring in a vessel provided with a descending condenser. A mixture passes over which contains methylene chloride, water and, at first, a little acetaldehyde; after condensation by cooling, the mixture is led for example into a U- 'tube or other vessel suitablefor separating different layers of liquids. In this way the mixture separates into its components. The methylene chloride, together with the acetaldehyde dissolved therein, is separated from the aqueous layer and returned to the reaction vessel. As soon as 18 parts of water have passed over, the reaction is completed. The solution of the condensation product in methylene chloride is washed with water, the methylene chloride then being distilled off with steam. In this manner a solid white mass is obtained which may be employed for example as a substitute for celluloid for the preparation of films or lacquers.

Example 2 1'75 parts of polymeric vinyl acetate prepared by a polymerization with the aid of l perthousand of benzoyl peroxide at 72 C. are dissolved in a mixture of 250 parts of-methylene chloride and 72 parts of butyraldehyde, a solution of 1 part of'phosphoric acid in 200 parts of n-butyl alcohol being added. The reaction mixture is then.heated to boiling whilestirring in the apparatus described in Example 1 until about Ill parts of water have passed over. solvents employed (methylene chloride and butyl alcohoDand the butyl acetate formed during the reaction areexpelled with steam. The condensation .product is a solid mass which dissolves in chlorinated aliphatic or aromatic hydrocarbons (such as methylene or ethylene chlorides and chloi'benzene) benzene and esters, such as ethyl or butyl acetates, and which may be employed as a substitute for celluloid for the preparation of films or lacquers.

Example 3 Example 4 88 parts of polymeric vinyl alcohol obtained by the saponification of polymerized vinyl acetate, are introduced while stirring into a mixture of 300 parts of methylene chloride, 36 parts 01' butyraldehyde, 92 parts of lauric aldehyde and 0.1 part of concentrated sulphuric acid, the mixture then being heated to boiling in the apparatus described in Example 1 until about 18 parts of water have passed over. The reaction product is worked up in the manner described in Example 1 and constitutes a colourless mass which is somewhat intermediate of those obtained according to Examples 2 and 3 as regards its properties.

After washing with water, the

Example 5 I A mixture bf 1'72 parts of polymeric vinyl acet'ate, 300 parts of anhydrous thyl alcohol, 72

parts of butyraldehyde and 8 parts of conceri- 5 trated sulphuric acid are heated to boiling while sti g under a reflu r condenser after the addition of 100 parts 01' dehydrated sodium sulphate until the reaction mixture no longer shows the Example 6 as parts of pol meric vinyl alcohoLprepared by the saponification oi polymerized vinylchloracetate, are suspended in a mixture of 200 parts 20 and 0.05 part of concentrated sulphuric acid in the apparatus described in Example 1 and the whole is heated to boiling while stirring until 0.3 part of water has been distilled off. The mixture is then allowed to cool and the reaction product is filtered oil by suction. It is a white powder which still dissolves in water but the aqueous solutions of which have a'considerably higher viscosity than aqueous solutions of the same concentration oi polymeric vinyl alcohol.

w a 'EEramplc7 Q -A mixture of 88 parts oi polymericvinyl alcohol, prepared by the saponification of polymeric 35 vinyl acetate, 128 parts of 2-ethylcapro'nic alde- Yde r v w t I f I alls 5 0.5 part of phosphoric acid of 85' per cent strength and 500 parts of chloroform are heated to boil-- ing while stirring in the'apparatus described in Example 1, 18' parts or water have been distilledoflf. The mixture is then allowed to cool .45 and the chloroiormic solution is washed with water until the eflluent water is neutral. chloroform is thenremoved by distillation with steam. The resulting reaction product is a white powder which is soluble in chlorinated hydrocar-' 50 bons such as methylene chloride, ethylene chloride or monochlorbenzene and inaromatichydrO-L arbons such as benzene ortoluene. The product 'may find useful application as an insulating materlal for electric devices.

What we claim is:--

1. The process for the aldehyde reaction. After'distilling oil the sol-' oi methylene chloride, 1.2 parts of butyraldehyde The materials by condensing-a polymeric vinyl alcohol with an aldehyde which comprises carrying out the condensation in a medium not miscible with water while removing the water formed during the reaction. v

'2. The process for the production of artificial materials by condensing a polymeric vinyl alcohol with an aliphatic aldehyde which comprises carrying outthe condensation in a medium not,

miscible with water while removing the water formed during the reaction.

t 3 The process for the production of artificial materials by condensing a polymeric vinyl alreaction.- v

-materials by condensing a polymeric vinyl alcocohol with an aliphatic aldehyde which comprises carrying out the condensation in a medium not miscible with water while absorbingthe ,water,

during the reaction, by means of a neutral substance having a strong water absorbing action. 4. The process for the production of artificial 20 hol with an aliphatic aldehyde which comprises carrying out .the' condensation in a water-insoluble inert diluent, the water formed being distilled ofi together with said diluent during the r v 5.'The process for the production of artificial materials by condensing a polymeric vinyl alcohol with an aliphatic aldehyde which comprises car-' rying out the condensation in a water-insoluble inert diluent, the water formed being ,contin-' uously distilledoff together with said'diluent, during. the reaction and separated from the distillate, the residual,'substantially anhydrous dilcible with water and in the presence of a monohydric aliphatic alcohol while removing the water formed during the reaction.

uent being returned to the reaction. I

6. The process for the production oft artificial materials by condensing a polymeric vinyl alcohol with an aldehyde which comprises carrying out the condensation with a polymeric vinyl carboxylate and an aldehyde in a medium not mis- 7. The process-tor the production of artificial materials bycondensing a polymeric. vinylalcohol with an aliphatic aldehyde containing more than 4 carbon atoms which comprises carrying out the condensation in a water-insoluble inert diluent, the water formed being continuously distilled oflf together with said diluent during the reaction and separated fromthe distillate, the 50 residual, substantially fianhydrous diluentbeing production 01' artEcial I returned to the reaction.

-8. A condensation product from a polymeric vinyl alcohol andZ-ethyl capronic aldehyde.

ERicH KUEHN.

j x HEINRICH H OPFE. 

